For then it would be open to question whether one is dealing with a concept which is possible but which can correspond to no possible reality, or rather with the concept of something truly real.9 In contrast to these different possible dialectical ways in which the initial concept of a universal becoming can be used, Whitehead's categoreal system aims to
describe it unmistakably as the fundamental
truth: «The
ancient doctrine that «no one crosses the same river twice,» is extended.